Forum: Ruby uninitialized constant NArray (Name Error)

Following section (2) here:
http://ruby.gfd-dennou.org/tutorial/gokuraku/index-e.html

Trying to run this part of script I have so far:

require 'narray'
ary1 = NArray.sfloat(3,4)

I get the following error:


C:\Users\Abder-Rahman\Desktop>ruby narray.rb
./narray.rb:2: uninitialized constant NArray (NameError)
        from narray.rb:1:in `require'
        from narray.rb:1

How can this issue be solved?

Thanks.

Abder-Rahman Ali wrote:
> Following section (2) here:
> http://ruby.gfd-dennou.org/tutorial/gokuraku/index-e.html
> 
> Trying to run this part of script I have so far:
> 
> require 'narray'
> ary1 = NArray.sfloat(3,4)
> 
> I get the following error:
> 
> 
> C:\Users\Abder-Rahman\Desktop>ruby narray.rb
> ./narray.rb:2: uninitialized constant NArray (NameError)
>         from narray.rb:1:in `require'
>         from narray.rb:1
> 
> How can this issue be solved?

(1) Don't call your own script 'narray.rb', because then Ruby will think 
it has already loaded the narray library.

(2) Install the library narray.rb that you want to use. Probably from 
here:
http://narray.rubyforge.org/

Looks like you need to install the library
# install from source (requires compiler)
gem install narray

# Windows binary (MinGW version; works also with VC6 mswin32)
gem install narray --platform=x86-mingw32


From here http://narray.rubyforge.org/


PRELOAD:
irb(main):001:0> require 'narray'
LoadError: no such file to load -- narray
    from (irb):1:in `require'
    from (irb):1

INSTALL:
! gem install narray
Password:
Building native extensions.  This could take a while...
Successfully installed narray-0.5.9.7
1 gem installed
Installing RDoc documentation for narray-0.5.9.7...

Usage:
irb(main):004:0> require "rubygems"
=> true
irb(main):005:0> require "narray"
=> true
irb(main):006:0> ary1 = NArray.sfloat(3,4)
=> NArray.sfloat(3,4):
[ [ 0.0, 0.0, 0.0 ],
  [ 0.0, 0.0, 0.0 ],
  [ 0.0, 0.0, 0.0 ],
  [ 0.0, 0.0, 0.0 ] ]
irb(main):007:0>


________________________________
From: Abder-Rahman Ali <abder.rahman.ali@gmail.com>
Reply-To: <ruby-talk@ruby-lang.org>
Date: Thu, 2 Sep 2010 10:09:33 -0500
To: ruby-talk ML <ruby-talk@ruby-lang.org>
Subject: uninitialized constant NArray (Name Error)

Following section (2) here:
http://ruby.gfd-dennou.org/tutorial/gokuraku/index-e.html

Trying to run this part of script I have so far:

require 'narray'
ary1 = NArray.sfloat(3,4)

I get the following error:


C:\Users\Abder-Rahman\Desktop>ruby narray.rb
./narray.rb:2: uninitialized constant NArray (NameError)
        from narray.rb:1:in `require'
        from narray.rb:1

How can this issue be solved?

Thanks.

Thanks Brian.

I have renamed the .rb file as: nary.rb

When I run the script, I get the following:

C:\Users\Abder-Rahman\Desktop\Research>ruby nary.rb
nary.rb:1:in `require': no such file to load -- narray (LoadError)
        from nary.rb:1

Provided that I have installed the "narray" gem using:

gem install narray

And, just a small thing. When you said: "Don't call your own script 
'narray.rb', because then Ruby will think it has already loaded the 
narray library."

Can you just clarify this point?

Thanks.

Thanks Savard. That solved the issue.

Seems we had to do: gem install narray TWICE?!

@Brian, so the name narray.rb can remain as is.

Thanks all.

@Savard. This works if working through irb.

If I put the script in a .rb file "narray.rb", I get the following:


C:\Users\Abder-Rahman\Desktop\Research>ruby narray.rb
./narray.rb:2: uninitialized constant NArray (NameError)
        from narray.rb:1:in `require'
        from narray.rb:1

Why is that? Why cannot I get it running as throigh irb?

Of I insert

require "rubygems", I get the following:


C:\Users\Abder-Rahman\Desktop\Research>ruby narray.rb
./narray.rb:3: uninitialized constant NArray (NameError)
        from 
C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in
`gem_original_require'
        from 
C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in
`require'
        from narray.rb:2

Abder-Rahman Ali wrote:
> Thanks Brian.
> 
> I have renamed the .rb file as: nary.rb
> 
> When I run the script, I get the following:
> 
> C:\Users\Abder-Rahman\Desktop\Research>ruby nary.rb
> nary.rb:1:in `require': no such file to load -- narray (LoadError)
>         from nary.rb:1
> 
> Provided that I have installed the "narray" gem using:
> 
> gem install narray

If you're running ruby 1.8.x, you'll need

require "rubygems"   # << THIS IS MISSING
require "narray"

> And, just a small thing. When you said: "Don't call your own script 
> 'narray.rb', because then Ruby will think it has already loaded the 
> narray library."
> 
> Can you just clarify this point?

Ruby keeps tracks of which libraries it has already loaded - actually in 
a variable called $LOADED_FEATURES - so that if you require the same 
library a second time, it doesn't get re-loaded.

So when you do

   require 'narray'

it will be skipped if narray.rb has already been loaded.

Unfortunately, if your script is called narray.rb, and you run it from 
the command line, then narray.rb *has* already been loaded, so line 1 of 
your script is skipped. It then continues to line 2, where it tries to 
use NArray and finds it undefined.

If you rename your script to nary.rb, then line 1 tries to find a file 
called narray.rb, and gives you a different error. You fix it by 
installing narray.rb somewhere in the library path (e.g. by installing 
the narray gem, and doing require 'rubygems')

@Brian. Thanks a lot. You are correct.

It runs now without errors, but the remaining case is, how can I display 
the result (Array) as the one that appeared when running the program 
using "irb"?

It displayed the result when I typed the following in the script:

p nary1

Thanks.

Ali,

YW! :-)

In the end I agree with Brian, you should not call it narry.rb

Cheers,
j

________________________________
From: Abder-Rahman Ali <abder.rahman.ali@gmail.com>
Reply-To: <ruby-talk@ruby-lang.org>
Date: Thu, 2 Sep 2010 10:48:50 -0500
To: ruby-talk ML <ruby-talk@ruby-lang.org>
Subject: Re: uninitialized constant NArray (Name Error)

Thanks Savard. That solved the issue.

Seems we had to do: gem install narray TWICE?!

@Brian, so the name narray.rb can remain as is.

Thanks all.

Again, I think Brian explained this and quite accurately.

I named my file gonary.rb

contents
require "rubygems"
require "narray"

ary1 = NArray.sfloat(3,4)
puts ary1.inspect
----------------------------
Results
----------------------------
<MANISH.local:jes> [09-03 07:03] 0 503:3  (0.16 Mb) ? ~/dev/noodle
! ruby gonary.rb
NArray.sfloat(3,4):
[ [ 0.0, 0.0, 0.0 ],
  [ 0.0, 0.0, 0.0 ],
  [ 0.0, 0.0, 0.0 ],
  [ 0.0, 0.0, 0.0 ] ]


See??

Cheers mate,
j



________________________________
From: Abder-Rahman Ali <abder.rahman.ali@gmail.com>
Reply-To: <ruby-talk@ruby-lang.org>
Date: Thu, 2 Sep 2010 10:54:30 -0500
To: ruby-talk ML <ruby-talk@ruby-lang.org>
Subject: Re: uninitialized constant NArray (Name Error)

@Savard. This works if working through irb.

If I put the script in a .rb file "narray.rb", I get the following:


C:\Users\Abder-Rahman\Desktop\Research>ruby narray.rb
./narray.rb:2: uninitialized constant NArray (NameError)
        from narray.rb:1:in `require'
        from narray.rb:1

Why is that? Why cannot I get it running as throigh irb?

Of I insert

require "rubygems", I get the following:


C:\Users\Abder-Rahman\Desktop\Research>ruby narray.rb
./narray.rb:3: uninitialized constant NArray (NameError)
        from
C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in
`gem_original_require'
        from
C:/Ruby187/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in
`require'
        from narray.rb:2

Thanks @Savard.